📦 Volume Formulas

Question 1

Why is volume of a rectangular prism
l x w x h?

Answer 1

Volume = how much 3D space it takes up. Each layer is a rectangle (area = l × w). Stack up h layers → multiply by height.

Question 2

Why is volume of a cylinder
πr^2h?

Answer 2

The base is a circle (πr^2). Each layer stacked is a circle. Stack h circles → multiply by height.

Question 3

Why is volume of a pyramid 1/3 x base area x h?

Answer 3

A pyramid has the same base and height as a prism, but it “tapers” to a point. It actually takes 3 pyramids to exactly fill 1 prism → so volume is one-third.